This invention is concerned with a method of interpolation of any quantity in any point of a sphere as well as with a device to determine an said electrical value and a device to display the topography of a potential field.
It is concerned more particularly with tests of functional exploration in neurology consisting in reading out from the electroencephalogram the brain's electric response as caused by applying a physiological stimulation (acoustical, visual, somesthesical stimulation)to the subject. The response is collected by means of several electrodes distributed over the scalp.
In the existing art, a great number of electrodes are used, that are evenly distributed on the whole spherical surface. The evaluation of the measures between two acquisition points is made by methods of interpolation which do not ensure an adequate accuracy.